This specification describes an audio system, for example for a vehicle, that includes directional loudspeakers. Directional loudspeakers are described generally in U.S. Pat. Nos. 5,870,484 and 5,809,153. Directional loudspeakers in a vehicle are discussed in U.S. patent application Ser. No. 11/282,871, filed Nov. 18, 2005. The entire disclosures of U.S. Pat. Nos. 5,870,484 and 5,809,153, and of U.S. patent application Ser. No. 11/282,871, are incorporated by reference herein in their entireties.